Our Ecobaby Interspring mattress with organic cotton and natural chemical free wool from organically raised sheep quilted to organic cotton mattress ticking is resilient and comfortable for baby. Your baby will delight in sleeping on the natural 6" thick mattress, free of chemical fumes. Passes all safety regulations and CPSC guidelines. Our crib mattresses are a 510 coil (242 Ellyptical actual coils - most crib mattresses are 180 coil - ours is firmer and will last longer. Get rid of that synthetic mattress that has been treated with a variety of chemicals, and treat your baby to the best! $35 additional shipping is included in the $34. price shown. (we recommend the organic wool moisture pad and the organic cotton mattress pad - to protect babys' mattress from wetness.